c. 1300, "grow weak, become enfeebled," also "lack courage or spirit, be faint-hearted," and "to pretend, feign;" from faint (adj.). Sense of "swoon, lose consciousness" is from c. 1400. Also used in Middle English of the fading of colors, flowers, etc. Related: Fainted; fainting. For Chaucer and Shakespeare, also a transitive verb ("It faints me").